<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        canvas {
            display:block;
            margin:20px auto;
            border:1px solid #ccc;
        }
    </style>
</head>
<body>
    <canvas width="800" height ='500'></canvas>
    <script>
        var cas = document.querySelector('canvas');
        var ctx = cas.getContext('2d');
        ctx.arc(200,200,100,0, 2*Math.PI );
        ctx.stroke();
        ctx.beginPath();
        ctx.translate(100,100);
        ctx.translate(100,100);
        ctx.arc(400,200,100,0, 2*Math.PI );
        ctx.stroke();
    </script>
</body>
</html>